We are studying the structure and function of three regulatory genes of E. coli: rho, crp and adenylate cyclase. We have cloned the rho gene first into bacteriophage lambda and then subcloned it into a multicopy plasmid. We have characterized the rho gene by restriction nuclease mapping and by functional analysis. We have also cloned a ts mutation in rho and found that the mutation is an IS1 insertion element. We have shown that mutations in cya or crp genes suppress some of the pleiotropic phenotypes associated with the ts mutants of rho. We are currently studying these relationships.